A blood sugar disorder, similar to diabeties. It causes confusion, unstabability, fainting, weakness and apathy. One has to regulate and be careful of what they eat. Sugar of any kind (candy, brownies, pasta, fruit) will cause their blood sugar to spike way up and then plummet, causing the negative effects. It can be a very slight problem, fixed by, say drinking water instead of sweet tea, or a serious problem that requires consistant balanced eating at regular intervals.

"Hey, are you okay? you look pathetic."
"I need something with protein in it- i have hypoglycemia. Give me food. right. now."